Flat file cabinets are commonly used to store and organize large-format, flat items, such as maps, architectural drawings and the like. The drawers of flat file cabinets are typically less than 3 inches high and have a relatively shallow holding capacity. However, each cabinet typically includes several such drawers arranged in a vertical column such that any one flat file cabinet can hold a large number of items.
To accommodate customary practice, the drawers of flat file cabinets are intentionally designed to be easily removable from and replaceable to the frame such that the items therein can be inspected at another location. In for example a library setting, this typically means removing the drawer from the flat file cabinet and taking it to a nearby table or stand. Therefore, the sliding support structure of the conventional flat file cabinets is designed to allow easy removal and replacement of the drawers.
The drawers are typically supported on frame bearings fixed to the frame which cooperate with drawer tracks attached to the drawers and drawer bearings attached to the drawers which cooperate with frame channels fixed to the frame. Typically, to remove a drawer, the drawer is first withdrawn, then the outward end of the drawer is lifted upward such that the drawer is oriented at an inclined angle. Then the drawer is withdrawn generally parallel to its angle of incline until free from the sliding support structure and frame. The drawer is replaced in the opposite motion.
To retain the drawers in the fully closed positions, the frame channels typically include slots or recesses adjacent the rearward ends thereof which cooperate with the drawer bearings affixed to the drawer. Specifically, when a drawer is fully closed, the drawer bearing drops into the slots or recesses in the frame channel, thereby somewhat inhibiting the movement of the drawer. It can be appreciated, however, that the cooperation of the slots and recesses and the drawer bearing provide only a limited amount of resistance to the movement of the drawer. This limited resistance is easily overcome by outward pressure on the drawer or a disturbance of the frame. Thus, drawers can open unintentionally, and moreover, multiple drawers can open simultaneously which can cause the frame to become unstable and fall over. Therefore, what is desired is a flat file cabinet which provides a means to interlock the various drawers thereof such that only one drawer may open at a time while retaining the ability to easily remove and replace the drawers in accordance with the common use of such flat file cabinets.
The flat file cabinet of the present invention provides a drawer interlocking system which prevents the simultaneous withdrawal of more than one drawer while retaining the ease and ability of temporarily removing and then replacing a drawer for inspection of the items contained therein. Specifically, the flat file cabinet includes a vertical column of locking bars slidably supported by the frame of the cabinet adjacent the front thereof. The locking bars include a pin and a roller at opposite ends thereof, which cooperate with interlocking channels affixed to the sides of the drawers. Each interlocking channel includes a tapered, arrow-shaped portion on the forward end thereof which cooperates with the roller of an associated locking bar to separate and displace the locking bars when the drawer is withdrawn. As will be discussed further below, the displacement of the adjacent locking bars prevents any other drawer from opening.
The interlocking mechanism is specifically designed to allow the normal operation of the flat file cabinet. Specifically, the drawers can be removed from the filing cabinet in a manner similar to prior designs by simply withdrawing the drawer, lifting the front end upward, then removing the drawer generally parallel to the angle of incline of the drawer until free from the support structure and frame. The removed drawer is replaced with an opposite motion. Importantly, when a drawer is fully removed, the locking bars return to a normal or rest position and function to provide the normal interlocking function for the remaining drawers.